The present invention relates to a control device for a system for distributing an airflow of a motor vehicle, which is more particularly suitable for a heating or air-conditioning installation.
In the present-day vehicles, the space reserved on the dashboard for controls in general is more and more constricted since provision is always being made for installing new equipment such as compact-disc players or, more recently, combinations of the radio/compact-disc player/satellite-guidance system type. However, the devices for control of functions such as the demisting, the ventilation or air-conditioning are vital for the comfort and the safety of the passengers. These controls therefore have to be easily accessible, offer ease of handling and be easily identifiable whilst taking up the least possible amount of space. The sophistication of these ventilation systems, moreover, has increased the possible number of functions, and has therefore complicated their control.
One solution to this problem has already been proposed in the patent FR 1 447 250. This solution consists in using a single control making it possible to set up the intensity, the temperature and the sharing of the throughput of an airflow sent into the passenger compartment of the vehicle. To do that, recourse is had to a single control handle provided on the end of a stalk which can slide from front to rear (opening or closing of the demisting for example), turn about its own axis (adjustment of the temperature) and pivot in a vertical axis perpendicular to the axis of the stalk (adjustment of the throughput).
However, not only is this solution not at all aesthetic, but it additionally requires large amplitudes in the movements of the stalk, especially for its axial translation and its rotation in the vertical axis. This therefore means reserving a lot of space in the dashboard, and especially a fairly substantial and ungainly horizontal cut-out. Moreover, the combination of a translational movement and of two rotational movements makes the device more fragile and very complicated to manipulate. Finally, because of the possible combination of the various movements and of the use of cables, the movements of the stalk are not really independent of one another. For example, by pivoting the stalk around the vertical axis in order to adjust the throughput, it is also possible to cause a slight action on the cable for the temperature adjustment whenever a support plate for this cable is made to turn. It will therefore be understood that, in this field, many improvements may be made.
The object of the present invention is therefore to resolve these problems at least partly by proposing a solution which is simple to implement, easy to use, compact, aesthetic (possible integration into numerous dashboards) and inexpensive.
To that end, the invention relates to a mechanical control device making it possible to act on control members of an airflow-distribution system for a motor vehicle, characterised in that it comprises at least two separate control means with rotary movement acting respectively independently with respect to one another on the control members, a first control means being mounted turning about a first rotational axis and carrying a second control means mounted turning about a second rotational axis which is inclined with respect to the first rotational axis.
The second control means is preferably articulated onto the first control means and turns about the second rotational axis which is perpendicular to the first rotational axis.
In particular, the first control means is a central knob equipped with a slot and the second control means is articulated in the said slot.
Advantageously, the second control means will feature means for transmitting a translational movement, by turning about the second rotational axis, along the first axis to a rod which features means for converting this translational movement into a rotational movement about a third rotational axis perpendicular to the first axis, this rotational movement being transmitted to a lateral control piece.
In particular, the second control means could be a knurled wheel which will then feature, internally, a straight-toothed-wheel portion turning about the second rotational axis so as to act on a straight-toothed rack gear extending along the first axis and integral with the rod, the said rod being equipped, furthermore, at the opposite end to the rack gear, with a succession of parallel grooves which act axially like teeth in engagement with a toothed wheel of the lateral control piece.
According to another aspect of the invention, the rotary central knob is linked to one end of a first shaft turning about the first rotational axis, this shaft featuring means for converting its rotational movement into another rotational movement about a fourth rotational axis perpendicular to the first axis so as to cause a first control lever to turn.
In particular, the first shaft of the control knob is equipped, at its opposite end, with a conical gear in engagement with a conical toothed-wheel portion of the first control lever.
In the concern for optimisation of the integration of the controls, the rod is hollow and surrounds the first shaft of the central knob so as to be able to slide axially outside this shaft along the first rotational axis.
Still with a concern for optimisation of the number of pieces present in the mechanism, the central knob internally features two lugs, spaced apart and parallel to the first rotational axis, these lugs each being traversed by a hole with its axis perpendicular to the first axis so as to accommodate an internal tubular part of the knurled wheel for the articulation of the latter about the second rotational axis.
In a variant, the central knob could feature two lugs spaced apart and parallel to the first rotational axis, these lugs then being equipped with protuberances interacting with a tubular part of the knurled wheel for the articulation of the latter about the second rotational axis.
In order to transmit the rotational movement of the central knob to the first shaft, the latter is equipped axially, at its end for linking to the central knob, with a notch defining a link with the tubular part of the knurled wheel.
In order to be able to shift the knurled wheel in any position of the central knob, the said knurled wheel also features means for rotationally driving the rod by way of the rack gear.
In particular, these means consist of two parallel walls extending along the first rotational axis and situated in the immediate vicinity of the toothed wheel so as to surround the rack gear on either side, acting as a lateral drive abutment.
Still with a concern for integration of the controls, the device further comprises a third control means arranged around the first means and movable in rotation about the first rotational axis.
In particular, this third control means consists of an outer ring turning about the first rotational axis and equipped with means for causing a second shaft to turn about a fifth rotational axis parallel to the first axis, this shaft featuring means for converting its rotational movement into another rotational movement about a sixth rotational axis perpendicular to the first axis XI so as to cause a second control lever to turn.
The ring preferably features a straight-pinion portion arranged on its outer periphery and the teeth of which are in engagement with a straight gear mounted at one end of the second shaft, the said shaft, at its other end, featuring a worm screw acting on a straight toothed-wheel portion of the second control lever.
According to other characteristics of the invention:
the first control means acts on the spatial location of the airflow;
the second control means acts on the temperature of the airflow;
the third control means acts on the power of the airflow;
the control means and the control members are produced from plastic.